Wireless devices can now handle voice and/or data, allowing simplex and/or duplex voice calls, video calls, text messaging, and internet browsing. Some wireless communication devices can now handle voice-over-internet-protocol (VoIP) calls, and others are able to handle multimedia (voice, video, graphics) calls through the wireless networks and/or through wireless networks connected to the internet or media servers.
Different types of calls, initiated by wireless devices, can be restricted for some or most of their outgoing traffic; for example voice and data calls, as well as internet web browsing, can be restricted to those calls tariffs made available by the wireless network(s) that is subscribed to. Those wireless networks could be traditional wireless network operators or so called virtual network operators. The restrictions can even limit which web servers the user is actually allowed to access; in most or all cases the restrictions will limit the users in their home country to only one wireless network, i.e. the home wireless network to which the user is subscribed to.
Users of wireless devices subscribed to a specific wireless network in their home country, may however wish to have a choice of call set-up route(s), and also have the choice of viewing any web server or web-page that they desire, and to initiate their outgoing calls at the tariff of their choice and through any of the wireless network(s) available in their home country, as well as when roaming abroad. This would give each wireless device user the freedom to choose the cheapest option for each call set-up route for any outgoing traffic, such as outgoing-SMS, -voice call, -data call.
With existing systems however, this is very difficult because mobile network operators have little economic incentive to provide end-users with the freedom to choose the cheapest network for each call set-up route for any outgoing traffic, such as outgoing-SMS, -voice call, -data call. In fact, they have every economic incentive to make this very difficult. One mechanism that entrenches the network operators' ability to restrict such freedom is the fact that every network operator in effect has considerable control over each subscriber because each subscriber to a particular has to be registered in the home location register (HLR) of that operator in order to receive service. The ownership and control that a network operator has over its HLR constitutes a major entry barrier to competitors seeking to offer lower cost services.
Before summarising the invention, we will explain some background terms.
A Home Location Register (HLR) is a database that contains mobile subscriber information for all subscribers to an operator. It is owned and maintained by that mobile operator. A Visitor Location Register (VLR) is a database owned and maintained by a mobile operator. It contains temporary information about mobile subscribers that are currently located in a geographic area served by that mobile operator, but whose Home Location Register (HLR) is elsewhere.
HLR subscriber information includes the International Mobile Subscriber Identity (IMSI), service subscription information, location information (the identity of the currently serving Visitor Location Register (VLR) to enable the routing of mobile-terminated calls), service restrictions and supplementary services information. The HLR also initiates transactions with VLRs to complete incoming calls and to update subscriber data.
The IMSI is a unique non-dialable number allocated to each mobile subscriber that identifies the subscriber and his or her operator subscription. The IMSI is stored in the Subscriber Identity Module (SIM). The IMSI is made up of three parts (1) the mobile country code (MCC) consisting of three digits, (2) the Mobile Network Code (MNC) consisting of two digits, and (3) the Mobile Subscriber Identity Number (MSIN) with up to 10 digits.
When a mobile subscriber roams away from his home location and into a remote location (typically to a different country), SS7 messages are used to obtain information about the subscriber from the HLR, and to create a temporary record for the subscriber in the VLR. There is usually one VLR per operator. The VLR automatically updates the HLR with the new location information, which it does using an SS7 Location Update Request Message. The Location Update Message is routed to the HLR through the SS7 network, based on the global title translation of the IMSI that is stored within the SCCP Called Party Address portion of the message. The HLR responds with a message that informs the VLR whether the subscriber should be provided service in the new location.
Critical to an operator's ability to restrict what end-users can do is the fact that operators control their own HLR, which can be thought of as the gateway into the mobile communications system. Even ‘virtual mobile network operators’ (VMNOs) are in effect subservient to the mainstream network operators that manage the physical infrastructure because the VMNOs still need to access the HLRs of the network operators.